content: package com.android4dev.navigationview;
  
  import android.app.FragmentManager;
  import android.app.FragmentTransaction;
  import android.graphics.Bitmap;
  import android.graphics.BitmapFactory;
  import android.os.AsyncTask;
  import android.support.design.widget.NavigationView;
  import android.support.v4.widget.DrawerLayout;
  import android.support.v7.app.ActionBarDrawerToggle;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.support.v7.widget.Toolbar;
  import android.util.Log;
  import android.view.LayoutInflater;
  import android.view.Menu;
  import android.view.MenuItem;
  import android.view.SubMenu;
  import android.view.View;
  import android.widget.Toast;
  
  public class MainActivity extends AppCompatActivity {
  
      //Defining Variables
      private Toolbar toolbar;
      private NavigationView navigationView;
      private DrawerLayout drawerLayout;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          // Initializing Toolbar and setting it as the actionbar
          toolbar = (Toolbar) findViewById(R.id.toolbar);
          setSupportActionBar(toolbar);
  
          //Initializing NavigationView
          navigationView = (NavigationView) findViewById(R.id.navigation_view);
  
          //Setting Navigation View Item Selected Listener to handle the item click of the navigation menu
          navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
  
              // This method will trigger on item Click of navigation menu
              @Override
              public boolean onNavigationItemSelected(MenuItem menuItem) {
  
  
                  //Checking if the item is in checked state or not, if not make it in checked state
                  if(menuItem.isChecked()) menuItem.setChecked(false);
                  else menuItem.setChecked(true);
  
                  //Closing drawer on item click
                  drawerLayout.closeDrawers();
  
                  //Check to see which item was being clicked and perform appropriate action
                  switch (menuItem.getItemId()){
  
  
                      //Replacing the main content with ContentFragment Which is our Inbox View;
                      case R.id.inbox:
                          Toast.makeText(getApplicationContext(),"Inbox Selected",Toast.LENGTH_SHORT).show();
                          ContentFragment fragment = new ContentFragment();
                          android.support.v4.app.FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();
                          fragmentTransaction.replace(R.id.frame,fragment);
                          fragmentTransaction.commit();
                          return true;
  
                      // For rest of the options we just show a toast on click
  
                      case R.id.starred:
                          Toast.makeText(getApplicationContext(),"Stared Selected",Toast.LENGTH_SHORT).show();
                          return true;
                      case R.id.sent_mail:
                          Toast.makeText(getApplicationContext(),"Send Selected",Toast.LENGTH_SHORT).show();
                          return true;
                      case R.id.drafts:
                          Toast.makeText(getApplicationContext(),"Drafts Selected",Toast.LENGTH_SHORT).show();
                          return true;
                      case R.id.allmail:
                          Toast.makeText(getApplicationContext(),"All Mail Selected",Toast.LENGTH_SHORT).show();
                          return true;
                      case R.id.trash:
                          Toast.makeText(getApplicationContext(),"Trash Selected",Toast.LENGTH_SHORT).show();
                          return true;
                      case R.id.spam:
                          Toast.makeText(getApplicationContext(),"Spam Selected",Toast.LENGTH_SHORT).show();
                          return true;
                      default:
                          Toast.makeText(getApplicationContext(),"Somethings Wrong",Toast.LENGTH_SHORT).show();
                          return true;
  
                  }
              }
          });
  
          // Initializing Drawer Layout and ActionBarToggle
          drawerLayout = (DrawerLayout) findViewById(R.id.drawer);
          ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.openDrawer, R.string.closeDrawer){
  
              @Override
              public void onDrawerClosed(View drawerView) {
                  // Code here will be triggered once the drawer closes as we dont want anything to happen so we leave this blank
                  super.onDrawerClosed(drawerView);
              }
  
              @Override
              public void onDrawerOpened(View drawerView) {
                  // Code here will be triggered once the drawer open as we dont want anything to happen so we leave this blank
  
                  super.onDrawerOpened(drawerView);
              }
          };
  
          //Setting the actionbarToggle to drawer layout
          drawerLayout.setDrawerListener(actionBarDrawerToggle);
  
          //calling sync state is necessay or else your hamburger icon wont show up
          actionBarDrawerToggle.syncState();
  
  
  
  
  
  
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.menu_main, menu);
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. The action bar will
          // automatically handle clicks on the Home/Up button, so long
          // as you specify a parent activity in AndroidManifest.xml.
          int id = item.getItemId();
  
          //noinspection SimplifiableIfStatement
          if (id == R.id.action_settings) {
              return true;
          }
  
          return super.onOptionsItemSelected(item);
      }
  }
  